[1] : The Collaborative International Dictionary of English v.0.48

infinitesimal \in`finites"imal\, a. cf. f. infinit'esimal,
   fr. infinit'esime infinitely small, fr. l. infinitus. see
   infinite, a.
   infinitely or indefinitely small; less than any assignable
   quantity or value; very small.
   1913 webster

   infinitesimal calculus, the different and the integral
      calculus, when developed according to the method used by
      leibnitz, who regarded the increments given to variables
      as infinitesimal.
      1913 webster
see also:
infinite infinitesimal calculus 

[2] : WordNet (r) 2.0

infinitesimal calculus
     n : the branch of mathematics that is concerned with limits and
         with the differentiation and integration of functions
         syn: calculus, the calculus
see also:
calculus the calculus 

Infinitesimal >> I Words
Infinitesimal, definition of term: Infinitesimal
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Calculus >> C Words
Calculus, definition of term: Calculus
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